Diaphragm time delay switch



Dec. zo, 1966 R, H, vom 3,293,384

DIAPHRAGM TIME DELAY SWITCH Filed Feb. 12, 1965 2 Sheets-Sheet 1 IN VENTOR ROBERT H- VOIGT BY M ATTORNEYS Dec. 20, 1966 R, VO|GT DIAPHRAGM TIME DELAY SWITCH 2 Sheets-Sheet 2 Filed Feb. l2, 1965 FIGS INVENTOR ROBERT H. vo\sT BY HMM. Buda..

ATTORNEYS United States Patent Office 3,293,384 Patented Dec. 20, 1966 3,293,384 DIAPHRAGM TIME DELAY SWITCH Robert H. Voigt, Port Huron, Mich., assigner to Aseco, Incorporated, Port Huron, Mich., a corporation of Michigan Filed Feb. 12, 1965, Ser. No. 432,332 14 Claims. (Cl. 200-34) The present invention relates to electric switches and more particularly to an improved construction for delayed action switches.

Delayed action switches refer to those switches in which opening of the electrical circuit is delayed for a period of time after the switch has been manually actuated to the ofic position. Such switches are finding increasing use in areas where it is convenient to delay de-energization of an incandescent lamp for instance for a` time period sufficient to permit lighted and safe exit from the area.

A number of constructions have been heretobefore proposed for delayed action switches but these have generally suffered from one or more of the following defects. In many of such switches the time delay mechanism is too complex to permit the switches to be economically produced. In others the time delay mechanism functions erratically and it is not possible to accurately forecast the duration of delay for any given actuation of the switch within any close range. In still others no means is provided for adjusting the time delay mechanism so that the switch can be used only in those situations in which the factory set time delay meets the particular intended use. In those switches in which attempts have been made to provide for adjustments either a part must be replaced or in some other manner adjustment is made difficult and unreliable.

U.S. Patent No. 2,735,671 issued to F. O. Kuhn on February 21, 1956 discloses and claims a delayed action switch of the general type herein contemplated. Experience with switches constructed in accordance with the teachings of this patent has indicated that there are several disadvantages inherent in such switches which the present invention overcomes. The switch of the aforementioned patent utilizes a fluid cell cup and a diaphragm as the time delay means. The diaphragm is secured to the cup by a ring member to define a fiuid chamber. Actuation of the switch to the on position compresses the diaphragm and actuation to the off or delay position releases the diaphragm. Upon expansion of the diaphragm the electrical switch is opened. The time delay is accomplished by metering the flow of air back into the fluid chamber upon release of the diaphragm.

The particular means employed in the aforementioned v patent for exhausting the diaphragm comprises removing a chordal portion of the ring member so that as the diaphragm is compressed a portion of the edge thereof is forced away from the fluid cup to permit the escape of air. The means for metering the reentry of air comprises a thread extending through the center of the diaphragm.

The particular exhaust means of the construction disclosed in the Kuhn patent is rather complex and expensive to produce. The particular metering means of the Kuhn patent does not afford an accurate and reliable means of regulating the reentry of air and thereefore the expansion of the diaphragm will vary greatly during use. Further, it has been found to be very difficult to establish a consistent time delay period for switches manufactured by the same tooling and using the same parts. This is presumably because even the smallest difference in the size of the hole through which the thread extends or in the porosity of the thread itself will produce a wide variation in the time duration. Further, the particular metering means can not be adjusted except by replacing the diaphragm. In addition the other components which make up the switch are complicated to produce and dif'lcult to assemble.

The present invention provides a time delay switch in which a fluid cell and diaphragm similar to that employed in the Kuhn switch are utilized. However, unlike the Kuhn switch the ring member for retaining the diaphragm and for providing the exhaust means has been eliminated and a new readily adjustable and highly reliable metering means has been provided. The mechanical components which make up the remainder of the switch are much less complicated than those disclosed by Kuhn as will be more apparent as the description proceeds and co-operate in a different manner largely as the result of a new spring member to produce a new, quiet type, reliable and adjustable time delay electrical switch.

It is an object then of the present invention to improve time delay switches by providing a reliable time delay means for such switches.

It is another object of the present invention to permit the use of time delay switches in many different locations having different time delay requirements by providing a time delay means for such switches which may be readily adjusted.

It is another object of the present invention to reduce the cost of manufacturing and assembling time delay switches by providing a construction for such switches utilizing a minimum of relatively simply manufactured and simply assembled parts.

It is another object of the present invention to increase the reliability of time delay means for time delay switches by providing such a time delay means comprising a fluid cell cup, a diaphragm disposed over the cup to define a fluid chamber, means actuated upon expansion of the diaphragm to actuate the electric switch and an adjustable means for delaying expansion of the diaphragm.

Still further objects and advantages will readily occur to one skilled in the art to which the invention pertains upon reference to the following drawings in which like reference characters refer to like parts throughout the several views and in which,

FIG. 1 is a front elevational view of a time delay switch of the present invention mounted for use,

FIG. 2 is an enlarged longitudinal cross-sectional view of the preferred switch of the present invention and illustrating the switch in the on position,

FIG. 3 is a view similar to FIG. 2 but illustrating the switch in the off position, p

FIG. 4 is a perspective view of one component of the switch illustrated in FIGS. 2 and 3,

FIG. 5 is an enlarged fragmentary cross-sectional view illustrating a portion of the structure shown in FIGS. 2 and 3,

FIG. 6 is a cross-sectional view taken substantially on line 6-6 of FIG. 2 and enlarged somewhat for purposes of clarity,

FIG. 7 is a cross-sectional view taken substantially on line 7-7 of FIG. 3 and enlarged somewhat for purposes of clarity,

FIG. 8 is a fragmentary cross-sectional view taken substantially on line 8 8 of FIG. 2,

FIG. 9 is a perspective view of a preferred spring member of the present invention, and

FIG. l0 is a fragmentary view partially in section illustrating a portion of the structure of the present invention.

Now referring to the drawings for a more detailed description of the present invention a preferred time delay electric switch 10 of the present invention is illustrated in FIG. l as being mounted in a wall 12 in the conventional manner to provide control for an incandescent, lamp (not shown) or other electrical appliance.

3 The switch is enclosed by a conventional cover plate 14.

It is to be understood that although the switch 10 will be described as though it is to be used mounted in the position shown in FIG. 1 and that the various components of the switch 10will be designated in accordance with such a manner of mounting that the switch 10 can, if desired, be mounted in other positions than the vertical position illustrated.

Now referring to FIGS. 2 and 3 for a description of the preferred switch 10 it is therein illustrated as comprising a case 16. The case 16 is preferably molded of any suitable dielectric material and is formed to provide a rear wall 18, top and bottom walls 20 and 22, respectively, and as can best be seen in FIGS. 6 and 7, side walls 24. The rear wall 18 is inwardly thickened toprovide a vertically extending surface 26 as can best be seen in FIG. 7 disposed within the interior of the case 16. An annular seat 30 is formed in the surface 26 and a preferably fmsto-conical recess 32 is formed in the thickened portion concentrically with the seat 30. Cored portions 34 are formed in the thickened portion adjacent the top and bottom walls 20 and 22. Corner posts 36 extend inwardly from the inner surface of the rear wall 18 and are spaced somewhat from the top and' bottom. walls 20 and 22 respectively as can best be seen in FIGS.y 6 and 7 to dene slots 37.

A retainer 38 also preferably molded of any suitable dielectric material is adapted to be inserted into the open end of the case 16 and is supported by the corner posts 36. The retainer 38 is provided with a central rectangular opening 40 having upper and lower radially removed portions 42 contiguous with outwardly inclined surfaces 44. The outer surface 46 of the retainer 38 is provided with upper and lower recessed edges 48 which are disposed in a plane substantially parallel with the free edges of the side walls 24 and the top and bottom walls 20 and 22 when the retainer 38 is positioned against the corner posts 36.

A mounting plate 50 is adapted to overlie the retainer 38 and provides the means for securing the switch 10 in a conventional electric box (not shown). The mounting plate 50 is provided with a central rectangular opening 52 receiving the raised portion of the outer surface 46 of the retainer 38. The case 16 is provided with lips 54 disposed on the outer and upper edges of the top and bottom walls 20 and 22 and the mounting plate 50 is provided with inwardly turned portions 56 which as can best be seen in FIG. 8 are adapted to receive the lips 54 and thereby lock the retainer 38 against the corner posts 36 and the mounting plate 50 to the case 16.

The top and bottom walls 20 and 22 are provided with openings 58 adjacent the rear walls 18. A substantially L-shaped contact plate 60 is provided with a base portion 62 adapted to be inserted into the slot 37 defined intermediate the corner posts 36 and the bottom wall 22 as can best be seen in FIGS. 6-7. The base portion 62 is provided with a threaded opening 64 which carries a terminal screw 66. The opening 58 permits an electrical lead (notshown) to be attached to the screw 66. A leaf portion 68 of the contact plate 60 carries an electrical contact 70.

A substantially L-shaped terminal plate 72 is provided with a base portion 74 adapted to be inserted into the slot 37 defined intermediate the corner posts 36 and the bottom wall 22. The base portion 74 is provided with a threaded opening 76 which carries a terminal screw 78. The opening 58 permits an electrical lead (not shown) to be attached to the screw 78.

A leaf portion 80 of the terminal plate 72 carries a leaf spring member 82 by means of a rivet 84. The leaf spring member 82 is constructed of a resilient material and is supported on the outer surface of the leaf portion 80 of the terminal plate 72. As can best be seen in FIGS. 4 and 6 the leaf spring member 82 preferably comprises an outer substantially rectangular portion 86 enclosing a tongue portion 88. The tongue portion 88 is integrally connected at one edge to the portion 86 and is provided at its opposite edge with a tab 90. The portion 86 is provided with a tab 92 extending closely adjacent the tab 90. The portion 86 is also provided with a perforation 94 which provides the means for mounting an electrical contact 96.

As can best be seen in FIG. 9 a flat substantially U-shaped spring 98 is provided with slots 100 adjacent each end thereof which receive the tabs and 92 respectively. p

The side walls 24 of the case 16 and the corresponding portions of the retainer 38 are formed to provide a pair of opposed annular mounting recesses 102 as can best be seen in FIG. 10. A control lever 104 is provided with cylindrical projections 106 which extend into the mounting recesses 102 so that the control lever 104 is pivotably mounted within the case 16 and the retainer 38. The control lever 104 is provided with a lever portion 108 extending through the opening 40 of the retainer 38. Indicia is provided on the control lever 104 on each `side of the lever portion 108. The control lever 104 is provided with a cam portion 112 engaging the tongue portion 88 of the leaf spring member 82 and operable at one pivotal position of the control lever 104 to depress the tongue portion 88 away from the portion 86 as shown in FIG. 2 and at another pivotal position of the control lever 104 to permit the tongue portion 88 to be bent outwardly away from the portion 86 as shown in FIG. 3.

A circular diaphragm 111 having a central thickened portion 114 and a peripheral circular edge portion 116 is preferably formed of any suitable exible material such as rubber or the like and is disposed with the edge portion 116 engaging the annular seat 30 formed in the rear wall 18 of the case 16 to close the recess 32 and to form a tluid chamber 118. A spring 120 biased between the rear wall 18 and the thickened portion 114 aids in urging the diaphragm 112 toward the expanded position illustrated in FIG. 3.

As can best be seen in FIG. 5, the rear wall 18 is provided with a passage 122 registering axially with the recess 32 and a threaded opening 124 registering axially with the passage 122. A circular porous member 126 is carried in the opening 124 adjacent the passage 122 and is retained in position by an adjustment screw 128 received by the threaded opening 124. The porous member 126 is preferably saturated with nely divided silicon dioxide (SiOZ).

In FIG. 2 the switch 10 is illustrated in the on position so that the indicia 110 exposed through the opening 40 with the control lever 104 in this position would indicate that the switch 10 is in the on position. In this position the cam portion 112 of the control lever 104 urges the tongue portion 88 against the diaphragm 111 into the compressed or exhausted position illustrated in FIG. 2. Movement of the tongue portion 88 away from the portion 86 Iof leaf spring member 82 acts through the U-shaped spring 98 to urge the portion 86 outwardly to bring the contact 96 into engagement with the contact 70. The contact plate 60, the leaf spring member 82, and the terminal plate 72 are constructed of electrical conducting material so that upon engagement of the contacts 70 and 96 an electrical path is connected between the terminal screws 66 and 78.

Upon pivotal movement of the control lever 104 in a clockwise direction from t-he position shown in FIG. 2 the indicia 110 disposed on the opposite side of the lever portion 108 is brought into View through the opening 40 and would indicate that the switch 10 is in the delay position. control lever 104 is moved axially along the tongue portion 88 away from the free end thereof so that the free end of the tongue portion 88 can ex in a direction away from the diaphragm 111. This flexing movement however is prevented by the U-shaped spring member 98 In this position the cam portion 112 of the` which maintains the contacts 70 and 96 in an engaged position until a force is applied to the spring member. 98 to urge it to an over center position. Once the spring member 98 is urged to an over center position it acts to urge the tongue portion 88 and the portion 86 to separate and since the tongue portion 88 is permitted by the cam portion 112 to move only slightly the portion 86 is urged in an inward direction to separate the contacts 70 and 96 and to open the switch 10 as shown in FIG. 3.

The desired time delay between actuation of the control Alever 104 and opening the contacts 70 and 96 is accomplished by providing a force operable to urge the U-shaped spring member 98 to an over center positionl only after a lpredetermined'time period has elapsed. Thisforce is provided by the central thickened portion 114 of t-he diaphragm 111 engagingv the tongue portion 88 and moving t-he tongue portion 88 outwardly upon expansion of the diaphragm 111 from the exhausted position shown` in FIG. 2 to the expanded position shown in FIG. 3. The expansion of the diaphragm 111 is delayed for a predetermined time period after the compressive force of the tongue portion 88 is released by metering the return of air into the uid chamber 118. The spring 120 is not of suiiicient force to overcome the atmospheric pressure acting on the outer surface of the diaphragm 111 so that until air is permitted to ll the uid chamber 118 the diaphragm 111 will not expand.

The air returns to the released diaphragm past the threaded portions provided in the opening 124 and on the adjustment screw 128 and through the porous member 126 and passage 122. By tightening or `loosening the screw 128 and thus varying the compression of the porous member 126 it is possible to adjust the rate at which air will reenter the fluid chamber 118. This provides a ready and accurate means of adjusting ther time delay period without requiring disassembly of the switch or replacement of parts.

When the control lever 104 is rotated from the delayt or oit position to the ony position shown in FIG. 2 the cam portion 112 is again brought into engagement with the tongue portion 88 and moves the tongue portion 88 inwardly to compress the diaphragm 111 and to act through the spring 98 to urge the contacts 70 and 96 into engagement. As the diaphragm 111 is compressed by the tongue portion 88 air escapes from the fluid chamber 118 by forcing the peripheral edge portion 116 away from the seat 30. The edge 116 returns to sealing engagement with the seat 30 once the diaphragm 111 assumes the compressed position.

It is apparent that a delayed action switch has been described having means permitting adjustment of the time delay period and without requiring that t-he switch be disassembled or new parts added to accomplish the adjustment. The tongue portion 88 is used to retain the diaphragm 111 in the seat 30 and no complex or expensive exhausting means for the diaphragm is required. The leaf spring member 82 and the U-shaped spring 98 provide an improved mechanical construction for the switch and provide a switch which is eicient and quiet in operation.

It is also apparent that although I have described but a single embodiment of my invention many changes and modifications can be made therein without departing from the spirit of the invention as expressed by t-he appended claims.

I claim:

1. In a delayed action switch having a pair of elec-f trical contacts and means for selectively moving said contacts into and out of engagement, said means comprising,

(a) spring means comprising a leaf spring member having a contact portion carrying one of said contacts and being movable intermediate a position engaging and disengaging said contacts,

(b) said leaf spring member further comprising a tongue portion connected wit-h said contact portion and movable relative thereto,

(c) ,said spring means further comprising a U-shaped spring member connected with said contact portion and said tongue portion and operable to urge separation of said portions whereby upon a force ybeing directed against said tongue portion in one direction said contact portion will be urged in the opposite direction,

(d) a lever member having a portion engaging said tongue portion and being operable upon movement toward a rst position to move said tongue portion in a irst direction and said contact portion through said spring member toward a position in which said contacts are in engagement,

(e) ,means operable upon said lever member being moved to a second position to urge said tongue portion in an opposite direction to thereby move said contact portion through said spring member toward a position in which said contacts are disengaged,

(f) said last mentioned means including a diaphragm engaging said tongue portion and moved to a collapsed position by said tongue portion upon movement of said lever member to a position engaging said contacts and operable in an expanded position to urge said tongue portion to a position disengaging said contacts and means delaying expansion of said diaphragm for a predetermined time period after movement of said lever member to said second position.

2. In a delayed action switch having a pair of electrical contacts and means for selectively moving said contacts into and out of engagement, said means comprising,

(a) spring means carrying one of said contacts and being operable at one position to bring said contacts into engagement and at another position to disengage said contacts,

(b) a lever member having a portion engaging said spring means and being operable upon movement toward a iirst position to urge said spring means toward said first mentioned position,

(c) means operable upon said lever member being moved to a second position to urge said spring means toward said second mentioned position,

(d) said last mentioned means comprising a liuid cell having a diaphragm, said diaphragm engaging said spring means and being moved by said spring means to an exhausted position upon said lever member being moved to said rst position and operable upon being moved to an expanded position to move said spring means toward said second mentioned position,

(e) means delaying movement of said diaphragm to said expanded position for a predetermined time period after movement of said lever member to said second position,

(f) said last mentioned means comprising a passage connected with said fluid cell, a porous member carried in said passage and means for varying the compression of said porous member whereby to adjust the rate of fluid entering said fluid chamber through said passage.

3. A delayed action switch comprising,

(a) a case and a lever member rotatably mounted in said case,

(b) a rst contact carried in said case and a spring means mounted in said case and carrying a second contact,

(c) said spring means being movable between a position engaging said contacts and a position disengaging said contacts,

(d) said lever member having a portion engaging said spring means and urging said spring means to said contact engaging position at one rotated position of said lever member,

(e) Said case being provided with a recess and a diaphragm closing said recess to define a fluid chamber,

(f) said diaphragm engaging said spring means and urging said spring means toward said contact disengaging position upon being moved to an expanded position,

(g) means exhausting said diaphragm upon movement of said lever member to said first mentioned rotated position and releasing said diaphragm at a second rotated position of said lever member, and

(h) means delaying expansion of said diaphragm member for a predetermined time period after release thereof, said means comprising a passage provided in said case and connected with said fluid chamber and means provided in said passage for restricting iiuid iiow therethrough.

4. The switch as defined in claim 3 and including means for adjusting the rate of fluid flow through said passage, said restricting means comprising a porous member and said adjusting means comprising means for varying the compression of said porous member.

5. The switch as defined in claim 3 and in which said spring means comprises,

(a) a leaf spring member having a contact portion carrying said second contact and a tongue portion resiliently connected with said contact portion, and

(b) a U-shaped spring member resiliently connecting said tongue portion and said contact portion and urging said portions to move in opposite directions.

6. The switch as defined in claim 5 and in which,

(a) said lever member engages said tongue portion and urges said tongue portion in one direction upon movement of said lever member to said rst mentioned rotated position, and

(b) said diaphragm engages said tongue portion and urges said tongue portion in an opposite direction upon expansion of said diaphragm.

v7. In a time delay switch having a spring means operable to delay opening of a pair of electrical contacts after a lever has been moved to a delay position until a force is exerted on the spring means, means for delaying the exertion of force for a predetermined time period com- Prising,

(a) a diaphragm engaging the spring means and enclosing a fluid chamber and operable upon being moved to an expanded position to exert the contact opening force, l

(b) an adjustable means delaying expansion of said diaphragm comprising a passage connected with said fluid chamber, a porous member carried in said passage to restrict the flow of iiuid through said passage and means for varying the compression of said porous member.

8. The switch as defined in claim 1 including a fluid cell provided with said diaphragm and said time delay means comprising metering means restricting the flow of fluid into said fluid cell upon collapse of said diaphragm to thereby delay the movement of said diaphragm from said collapsed position to said expanded position for a predetermined time period.

9. The switch as defined in claim 8 and including means for adjusting said metering means to vary the rate of flow into said fluid cell and to thereby vary the time delay before actuation of said tongue portion toward a position opening said contacts.

10. The switch as defined in claim 9 and in which said adjusting means comprises,

(a) a passage communicating with said fluid cell,

(b) a porous insert member carried in said passage,

(c) screw means carried in said passage for varying the compression of said porous member.

11. In a delay action switch having a pair of electrical contacts and means for selectively moving said contacts into and out of engagement, said means comprising:

(a) spring means carrying one of said contacts and,

at one position, bringing said contacts into engagement and at another position disengaging said contacts,

(b) actuating means having a portion engaging said spring means and being operable upon movement toward a first position to urge said spring means toward said first mentioned position,

(c) means operable upon said actuating means being moved to a second position to urge said spring means toward said second mentioned position,

(d) said last mentioned means comprising a fluid cell having a diaphragm, said diaphragm engaging said spring means, and being moved by said spring means to a collapsed position upon said actuating means being moved to said first position and operable upon being moved to an expanded position to move saidv spring means toward said second mentioned position,

(e) means delaying movement of said diaphragm to said expanded position for a predetermined time period after movement of said actuating means to said second position.

12. The switch as defined in claim 11 and in which said last mentioned means comprises a passage connected with said fluid cell, a porous member carried in said passage and means for varying the compression of said porous member whereby to adjust the rate of fluid entering said uid cell through said passage.

13. A delayed action switch comprising:

(a) a case and an actuating member mounted in said case,

(b) a first contact carried in said case and spring means mounted in said case and carrying a second contact,

(c) said spring means being movable between a first position engaging said contacts and a second position disengaging said contacts,

(d) said actuating member having a portion engaging said spring means and urging said spring means to said first position at one position of said actuating member,

(e) said case being provided with a recess and a diaphragm closing said recess to define a fluid chamber,

(f) said diaphragm engaging said spring means and urging said spring means toward said second position upon being moved to an expanded position,

(g) means exhausting said diaphragm upon movement of said actuating member to said first position and releasing said diaphragm at a second position of said actuating member,

(h) means delaying expansion of said diaphragm member for a predetermined time period after release` thereof.

14. The device as defined in claim 13 and in which said last mentionedmeans comprises a passage provided in said case and connected with said liuid chamber and means provided in said passage for restricting fluid fiow therethrough.

References Cited by the Examiner UNITED STATES PATENTS 1,942,040 1/ 1934 Wolff 200-34 2,735,671 2/1956 Kuhn 20G-34 X 2,866,862 12./1958 Bachi 200-.34 3,187,121 6/1965 Mingrone 20G- 34 BERNARD A. GILHEANY, Primary Examiner.

H. M. FLECK, G. I. MAIER, Assistant Examiners, 

1. IN A DELAYED ACTION SWITCH HAVING A PAIR OF ELECTRICAL CONTACTS AND MEANS FOR SELECTIVELY MOVING SAID CONTACTS INTO AND OUT OF ENGAGEMENT, SAID MEANS COMPRISING, (A) SPRING MEANS COMPRISING A LEAF SPRING MEMBER HAVING A CONTACT PORTION CARRYING ONE OF SAID CONTACTS AND BEING MOVABLE INTERMEDIATE A POSITION ENGAGING AND DISENGAGING SAID CONTACTS, (B) SAID LEAF SPRING MEMBER FURTHER COMPRISING A TONGUE PORTION CONNECTED WITH SAID CONTACT PORTION AND MOVABLE RELATIVE THERETO, (C) SAID SPRING MEANS FURTHER COMPRISING A U-SHAPED SPRING MEMBER CONNECTED WITH SAID CONTACT PORTION AND SAID TONGUE PORTION AND OPERABLE TO URGE SEPARATION OF SAID PORTIONS WHEREBY UPON A FORCE BEING DIRECTED AGAINST SAID TONGUE PORTION IN ONE DIRECTION SAID CONTACT PORTION WILL BE URGED IN THE OPPOSITE DIRECTION, (D) A LEVER MEMBER HAVING A PORTION ENGAGING SAID TONGUE PORTION AND BEING OPERABLE UPON MOVEMENT TOWARD A FIRST POSITION TO MOVE SAID TONGUE PORTION IN A FIRST DIRECTION AND SAID CONTACT PORTION THROUGH SAID SPRING MEMBER TOWARD A POSITION IN WHICH SAID CONTACTS ARE IN ENGAGEMENT, 